During Phase I research, surface modification of microporous membranes (MPM's) enabled cell culture inserts to support anchorage dependent cell growth without extra-cellular matrix coatings. For MDCK cultures, surface modification yielded growth surfaces which were equivalent to collagen; for bovine pulmonary artery endothelium cultures, surface modified MPM's far out-performed laminin coated membranes. Despite these successes, the desired control over surface chemistry was not achieved and XPS analysis yielded an incomplete chemical characterization of the surface. Thus, Phase II research will employ an improved means of surface modification and SSIMS surface analysis will also be utilized. Surface modified MPM's will be tested in four different cell culture systems and experiments will be performed to illustrate: 1) improved trans-monolayer permeability studies, 2) attainment of desired cell morphology, 3) primary cultures in serum free medium, and 4) improved visualization of cells. Finally, a reactor for the treatment of large numbers of MPM inserts, and devices enabling improved microscopic evaluation of cultures on MPM's, will be fabricated and tested.